Download To Local File

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare destructiveHint=true, readOnlyHint=false and idempotentHint=true, so safety is covered. The description adds genuinely new context: streaming behavior, no return payload, and the FTP_LOCAL_ROOTS write boundary. It does not spell out that an existing file is only replaced when overwrite is set, though the schema covers that.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tight sentences, zero filler. The streaming/no-contents behavior and the write-boundary constraint are both front-loaded where an agent will read them.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, and the description correctly notes that file contents are not returned, so return values need no explanation. The FTP_LOCAL_ROOTS restriction is the key non-schema constraint and it is stated. Only the interaction between overwrite and pre-existing files is left solely to the schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all three parameters are already documented, including overwrite's default. The description reinforces the local-root constraint on localPath but adds no syntax or format detail beyond the schema; baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (download) and resource (file), and pins the destination as a local path on this computer. The clause 'without returning its contents' implicitly separates it from the sibling download-file, which presumably returns contents, but it never names that sibling.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The 'straight to a path ... without returning its contents' phrasing implies when this tool is preferable to a contents-returning download, but no alternative or exclusion is stated explicitly. There is also no guidance on when to set overwrite versus leaving it at default.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.